JP2005249267A - Microwave oven - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microwave oven enabling a reduction in front surface dimensions and depth dimensions. <P>SOLUTION: A choke chamber 10 formed to come into a heating chamber 1 when a door 3 is closed is formed in the door 3. The choke chamber 10 is divided through an extension wall 19. Also, an adjusting wall 12 extended from one end of an opening 11 so as to come into contact with the wall surface of the heating chamber 1 and a communication port 22 communicating a first groove 20 with a second groove 21 are formed in the choke chamber 10. In this case, the width dimension A of the first groove 20 is desirably be formed smaller than the width dimension B of the second groove 21. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a microwave oven, and more particularly to a structure for preventing radio wave leakage from around a door that opens and closes an opening of a heating chamber.

Conventionally, for example, a structure described in Patent Document 1 is known as a structure for preventing leakage of electric waves from the periphery of a door that opens and closes an opening of a heating chamber in a microwave oven. FIG. 13 is a schematic cross-sectional view of the microwave oven according to this conventional example, and FIG. 14 is an enlarged cross-sectional view of the vicinity of the choke chamber of the door in the microwave oven.
As shown in FIGS. 13 and 14, the conventional one has a choke chamber 104 provided at the periphery of the door 103 that opens and closes the opening 102 of the heating chamber 101 at the periphery of the opening 102 of the heating chamber 101. It arrange | positions so that the front side of the flange 105 may be contacted. For this reason, the outer dimensions of the door 103 are such that the front dimension of the microwave oven is the vertical and horizontal dimensions of the opening 102 of the heating chamber 101, and the width dimension N (see FIG. 14) of the flange 105 as the sealing surface and the width of the choke chamber 104. There is a drawback that it is difficult to reduce the outer shape of the microwave oven because the size is larger than the dimension combined with the dimension M (see FIG. 14).

Moreover, the thing of patent document 2 is known as another technique regarding the electromagnetic wave leakage prevention structure from the surroundings of the conventional door 103. FIG.
The microwave oven door is provided with a choke formed so as to enter the heating chamber (oven) when the door is closed. Therefore, in this case, the front dimension of the microwave oven can be reduced. However, since this conventional choke has a simple square-shaped space, the depth of the choke becomes λ / 4, and the width of the door and the depth of the microwave oven increase. It was. Moreover, the radio wave leakage effect of the choke was not sufficient.
Japanese Patent Laid-Open No. 63-43287 FIG. 2 JP, 59-48517, A FIG. 2, FIG. 5, FIG.

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a microwave oven in which the front dimension and the depth dimension can be reduced.

  Moreover, the microwave oven according to the first solution means according to the present invention has a heating chamber in which radio waves are supplied, and a door that opens and closes the opening of the heating chamber, and the door becomes a heating chamber when closed. The choke chamber has a choke chamber formed so as to enter, and the choke chamber extends from the front end of the heating chamber to the front surface of the heating chamber in close proximity to or in contact with the wall surface of the heating chamber. An adjustment wall, an outer side wall facing the heating chamber wall from the rear end of the opening at a predetermined interval, a bottom wall formed on the rear surface orthogonal to the outer side wall, and formed on the front surface orthogonal to the adjustment wall A front wall, an inner side wall formed to face the adjustment wall and the outer side wall so as to connect the front wall and the bottom wall, and a protruding wall extending from the rear end of the opening toward the inner side wall into the choke chamber A first groove formed on the opening side of the overhanging wall, and a bottom wall side of the overhanging wall. A second groove which is, formed between the tip and the inner side wall of the bulging walls, and having a communication port communicating the first grooves and the second grooves.

  A microwave oven according to a second solution means according to the present invention has a heating chamber in which radio waves are supplied and a door for opening and closing the opening of the heating chamber, and the door enters the heating chamber when closed. The choke chamber has an opening formed so as to face the wall surface of the heating chamber, and extends rearward from the rear end of the opening in proximity to or in contact with the wall surface of the heating chamber. An adjustment wall, an outer side wall facing the heating chamber wall from the front end of the opening at a predetermined interval, a bottom wall of the choke chamber formed on the front surface orthogonal to the outer side wall, and a rear surface orthogonal to the adjustment wall A rear wall formed on the inner wall, an inner side wall formed to face the outer side wall and the adjustment wall so as to connect the bottom wall and the rear wall, and an overhang extending from the front end of the opening toward the inner side wall into the choke chamber A wall, a first groove formed on the opening side of the overhanging wall, and a bottom surface of the overhanging wall A second groove formed on the side, which is formed between the tip and the inner side wall of the bulging walls, and having a communication port communicating the first grooves and the second grooves.

  Further, the microwave oven according to each of the above solutions may be configured to have a stepped portion that allows the bottom wall of the choke chamber to come into contact with the front in the vicinity of the opening of the heating chamber.

  Further, the microwave oven according to each of the above-described solving means may be configured to have a stepped portion that allows the rear wall of the choke chamber to come into contact with the front in the vicinity of the opening of the heating chamber.

  Moreover, in the microwave oven which concerns on said each solution means, you may comprise so that the wall surface of a heating chamber may be formed in the taper shape extended toward the front in the opening part vicinity.

  In the microwave oven according to each of the solving means, the choke chamber is preferably formed so that a width dimension of the first groove is smaller than a width dimension of the second groove.

  Further, in the microwave oven according to each of the above solutions, the opening of the choke chamber may be formed so as to be covered with a dielectric.

  In the microwave oven according to each of the solving means, the choke chamber may have a periodic structure in which slits straddling the outer side wall and the overhanging wall of the choke chamber are provided at predetermined intervals.

  In the microwave oven according to the first (or second) problem solving means according to the present invention, the radio wave leaking from the heating chamber through the outer periphery of the door is from the opening of the choke chamber formed facing the wall surface of the heating chamber. Enter the chalk chamber. Further, according to this choke structure, the dimension of the adjustment wall extending forward (or rearward) from the front end (or rear end) of the opening of the choke chamber in proximity to or in contact with the wall surface of the heating chamber can be changed. Thus, the equivalent capacity C of the choke chamber can be adjusted, the equivalent impedance of the second groove can be adjusted by changing the size of each part of the second groove, and further, the gap between the tip of the overhanging wall and the inner side wall can be adjusted. The equivalent impedance of the communication port can be adjusted by changing the size of the communication port that communicates with the first groove and the second groove. Therefore, by adjusting these adjustment functions, it is possible to design an optimal choke chamber as a choke structure for a fundamental wave in a microwave oven, and it is possible to obtain a choke chamber that is smaller than the conventional one. In addition, radio waves leaking from the heating chamber to the outside can be attenuated by an adjustment wall extending forward (or rearward) in proximity to or in contact with the wall surface of the heating chamber.

  Further, in the microwave oven according to the first (or second) problem solving means, the heating chamber is configured so that the bottom wall (or rear wall) of the choke chamber can be contacted from the front in the vicinity of the opening of the heating chamber. If the wall surface is formed in a stepped portion, the bottom wall (or rear wall) of the chalk chamber can be brought into metal contact with the wall surface of the heating chamber when the door is closed. Therefore, radio waves leaking from the heating chamber to the outside due to this metal contact can be contained.

  In addition, in the microwave oven according to each of the above solutions, if the vicinity of the opening of the heating chamber is formed in a tapered shape that spreads forward, the adjustment wall and the tapered surface at the time of closing the door are not affected without opening and closing the door. Can be reduced. Therefore, it is possible to further improve the attenuation effect of leaked radio waves by the adjustment wall.

  In the microwave oven according to each of the above solutions, if the width dimension of the first groove of the choke chamber is formed smaller than the width dimension of the second groove, the characteristic impedance of the second groove is made larger than the characteristic impedance of the first groove. Therefore, the dimensions of the choke chamber can be easily reduced as compared with the conventional case.

  In the microwave oven according to each of the above solutions, if the opening of the choke chamber is covered with a dielectric, the intrusion of dust into the choke chamber is prevented without interfering with radio waves entering the choke chamber from the choke chamber opening. In addition, the opening of the chalk chamber can be hidden with a dielectric when the door is opened, and the appearance when the door is opened can be improved.

  In addition, in the microwave oven according to each of the above solutions, if a periodic structure is formed in which slits straddling the outer side wall and the overhanging wall of the choke chamber are provided at predetermined intervals, the propagation of radio waves along the sealing surface of the opening of the heating chamber is prevented. It is possible to prevent the leakage of radio waves leaking from the heating chamber to the outside.

  Hereinafter, each embodiment will be described with reference to the drawings.

A first embodiment of the present invention will be described with reference to FIGS.
1 is a schematic cross-sectional view of a microwave oven according to a first embodiment, FIG. 2 is an enlarged cross-sectional view of the vicinity of a choke chamber of a door 3 in the microwave oven, and FIG. 3 is a state in which the door of the microwave oven is closed It is a perspective view from the front side in. FIG. 4 is a perspective view from the front side in a state where the door of the microwave oven is opened, with the dielectric removed. FIG. 5 is a perspective view from the front side of the door in the microwave oven, with the dielectric removed.

  As shown in FIGS. 1 to 4, in the microwave oven according to the first embodiment, the opening 2 on the front surface of the heating chamber 1 is opened and closed by a door 3, as in a normal microwave oven. The heating chamber 1 is configured to be irradiated with radio waves from a magnetron (not shown), which is a high-frequency oscillator, via a waveguide (not shown). The opening 2 on the front surface of the heating chamber 1 has a key-shaped stepped portion 4 that expands forward, and a flange portion 5 is formed at the opening end of the stepped portion 4. The stepped portion 4 includes a shoulder wall surface 4 a that forms a shoulder parallel to the opening surface of the opening 2, and a depth direction wall surface 4 b that extends in the depth direction perpendicular to the opening surface of the opening 2.

  On the outer periphery of the front plate 6 of the door 3, a choke chamber 10 that enters the inside of the heating chamber 1, more specifically, enters the stepped portion 4 of the heating chamber 1, is formed so as to protrude. Further, a punching plate portion 7 is formed at the center portion of the front plate 6 to block radio waves by forming a large number of small holes.

  The chalk chamber 10 includes an opening 11 formed so as to face the wall surface (depth direction wall surface) 4 b of the heating chamber 1. Further, an adjustment wall 12 is provided that extends forward from the front end of the opening 11 in the vicinity of or in contact with the depth-direction wall surface 4b. Since the adjustment wall 12 is close to or in contact with the depth direction wall surface 4b, it is possible to attenuate radio waves leaking to the outside. A front wall 13 that forms the front surface of the choke chamber 10 is formed from the front end of the adjustment wall 12 in a direction perpendicular to the adjustment wall 12. The adjustment wall 12 and the front wall 13 use the outer peripheral end of the front plate 6 of the door 3, and the adjustment wall 12 is formed by bending the end of the front plate 6.

An outer side wall 15 is formed from the rear end of the opening 11 so as to face each other with a gap 14 at a predetermined interval between the heating chamber 1 and the depth direction wall surface 4b. An opening 11 is formed by the distal end portion of the adjustment wall 12 and the outer side wall 15, and the equivalent capacity C of the choke chamber 10 can be adjusted by adjusting the dimension D of the adjustment wall 12.
A plate-like dielectric 16 is bonded to a portion corresponding to the gap 14. The dielectric 16 prevents radio waves from accumulating in the choke chamber 10 while allowing radio waves to pass through the opening 11 of the choke chamber 10, and obstructs the opening 11 of the choke chamber 10 when the door 3 is opened. Thus, the appearance can be prevented.

  Further, the choke chamber 10 includes a bottom wall 17 that forms the rear surface of the choke chamber 10 in a direction perpendicular to the outer side wall 15. The bottom wall 17 forms a short-circuit surface of the choke chamber 10. Further, the bottom wall 17 is formed so as to be in metal contact with the shoulder wall surface 4a when the door 3 is closed. By making metal contact in this way, radio waves leaking from the heating chamber 1 through the periphery of the door 3 can be confined in the heating chamber.

  Further, the choke chamber 10 includes an inner side wall 18 formed to face the adjustment wall 12 and the outer side wall 15 so as to connect the front wall 13 and the bottom wall 17. Further, the choke chamber 10 includes a projecting wall 19 that extends from the rear end of the opening 11 into the choke chamber 10, that is, from the outer side wall 15 toward the inner side wall 18 in a right angle direction. The overhanging wall 19 divides the chalk chamber 10 into a first groove 20 on the opening 11 side and a second groove 21 on the bottom wall 17 side. A communication port 22 having a predetermined size for communicating the first groove 20 and the second groove 21 is formed between the tip of the overhanging wall 19 and the inner side wall 18. The width A of the first groove 20 is smaller than the width B of the second groove 21 (A <B).

  In general, in a microwave oven, radio waves leaking from the outer periphery of the door 3 can be divided into x, y, and z directions as shown in FIG. In the microwave oven according to the first embodiment, when the cross-sectional view of FIG. 2 is an xy plane, propagation of radio waves in the x and y directions is prevented by the choke chamber 10. Further, in order to prevent propagation of radio waves in the z direction, a periodic structure in which slits 23 extending from the outer side wall 15 of the choke chamber 10 to the overhanging wall 19 are provided at predetermined intervals is formed.

  In the microwave oven of the present embodiment configured as described above, since the bottom wall 17 and the shoulder wall surface 4a of the stepped portion 4 are both formed in parallel with the opening surface of the opening 2, the door 3 is closed. Both can be easily manufactured so as to be in metal contact. For this reason, radio waves leaking from the heating chamber 1 through the periphery of the door 3 are first enclosed in the heating chamber 1 by metal contact between the bottom wall 17 and the stepped portion 4, and the leaked radio waves are greatly reduced. can do. Further, since the adjustment wall 12 is formed so as to be close to or in contact with the depth direction wall surface 4b of the stepped portion 4, it is further attenuated at this portion.

  Of the radio waves that have passed through the metal contact portion between the bottom wall 17 and the stepped portion 4, radio waves in the z direction are leaked by a periodic structure in which slits 23 extending from the outer side wall 15 to the overhanging wall 19 are provided at predetermined intervals. Is prevented. Further, radio waves in the x and y directions enter the choke chamber 10 through the opening 11, and radio wave leakage is prevented in the choke chamber 10.

The radio wave leakage prevention structure of the choke chamber 10 is considered to be a resonance phenomenon of the cavity resonator, and the resonance frequency can be obtained from the equivalent inductance L and the equivalent capacitance C of the choke chamber 10. The equivalent capacity C of the choke chamber 10 can be easily adjusted by changing the length D of the adjusting wall 12 of the door front plate 6. The equivalent capacity C of the choke chamber 10 can also be easily adjusted by changing the dimension of the communication port 22 between the first groove 20 and the second groove 21. Furthermore, the equivalent inductance L can be easily adjusted by changing the dimension of the first groove 20.
Therefore, the choke chamber 10 according to the present embodiment can be designed to be a small choke chamber optimal for 2450 MHz, which is the fundamental wave of a microwave oven, by changing these dimensions. Can be smaller

  Further, in the microwave oven according to the present embodiment, the width dimension A of the first groove 20 is smaller than the width dimension B of the second groove 21, so that the characteristic impedance of the second groove 21 is greater than that of the first groove 20. Thus, the size of the choke chamber 10 can be easily reduced, and the depth direction dimension of the microwave oven can be reduced.

  Next, Example 2 will be described with reference to FIGS. 6 is a schematic cross-sectional view of the microwave oven according to the second embodiment, and FIG. 7 is an enlarged cross-sectional view of the vicinity of the choke chamber of the door in the microwave oven. In addition, the same code | symbol is attached | subjected to the same location as Example 1, and the description is abbreviate | omitted.

In Example 2, the shape of the opening 2 of the heating chamber 1 is changed in Example 1.
That is, in Example 2, as shown in FIGS. 6 and 7, the opening 2 on the front surface of the heating chamber 1 is a tapered portion 25 that expands forward. Further, the choke chamber 10 similar to that of the first embodiment is obliquely attached so that the adjusting wall 12 and the outer side wall 15 are along the tapered portion 25 according to the shape of the tapered portion 25 of the opening 2.
In the chalk chamber 10 in the second embodiment, the bottom wall 17 is not in metal contact with the wall surface of the heating chamber 1 because there is no stepped portion in the heating chamber 1, but the adjustment wall 12 is the heating chamber as in the first embodiment. It is attached so as to be in contact with or close to the wall surface of 1, specifically, the wall surface of the tapered portion 25.
The shape of the dielectric 16 is wedge-shaped unlike the first embodiment, but may be a flat plate as in the first embodiment.

  Since Example 2 is configured as described above, of radio waves leaking from the heating chamber 1 through the peripheral portion of the door 3, assuming the cross-sectional view xy plane of FIG. The radio wave of FIG. 4 according to the first embodiment is prevented from leaking in the choke chamber 10. Further, leakage of radio waves in the Z direction (see FIG. 4 according to the first embodiment) is prevented by a periodic structure in which slits 23 extending from the outer side wall 15 to the overhanging wall 19 are provided at predetermined intervals. Further, radio waves leaking from the heating chamber 1 through the peripheral portion of the door 3 are contained by the proximity or contact between the adjusting wall 12 and the wall portion of the tapered portion 25.

  Moreover, since the opening 2 of the heating chamber 1 is formed in a tapered shape, when the door 3 is opened, a gap between the adjustment wall 12 and the wall of the tapered portion 25 is increased. For this reason, the adjustment wall 12 and the wall part of the taper part 25 at the time of door closing can be made closer, and the electromagnetic wave leaked outside from the heating chamber 1 can be further reduced.

Next, Example 3 will be described with reference to FIGS. 8 is a schematic sectional view of the microwave oven according to the third embodiment, FIG. 9 is an enlarged sectional view of the vicinity of the chalk chamber of the door in the microwave oven, and FIG. 10 is a front side of the door in the microwave oven. FIG. In addition, the same code | symbol is attached | subjected to the same location as Example 1, and the description is abbreviate | omitted.
The third embodiment is obtained by changing the choke structure in the first embodiment.
As shown in FIGS. 8 to 10, in the microwave oven according to the third embodiment, the opening 2 on the front surface of the heating chamber 1 is opened and closed by the door 3 as in the microwave oven of the first embodiment, and the opening portion 2 on the front surface of the heating chamber 1. In addition, a key-shaped stepped portion 4 that expands forward is provided.

  Further, a choke chamber 40 that protrudes into the heating chamber 1, more specifically into the stepped portion 4 of the heating chamber 1, protrudes from the outer periphery of the door 3. In addition, a punching plate portion 37 that blocks radio waves by forming a large number of small holes is formed in the center portion of the front plate (sealing plate) 36.

  The chalk chamber 40 includes an opening 41 formed so as to face the wall surface of the heating chamber 1. In addition, an adjustment wall 42 extending from the rear end of the opening 41 to the rear side in close proximity to or in contact with the wall surface (depth direction wall surface) 4b of the heating chamber 1 is provided. Since the adjustment wall 42 is close to or in contact with the depth-direction wall surface 4b, radio waves leaking to the outside can be attenuated. A rear wall 43 that forms the rear surface of the choke chamber 40 is formed from the rear end of the adjustment wall 42 in a direction perpendicular to the adjustment wall 42. The adjustment wall 42 and the rear wall 43 use the outer peripheral end portion of the front plate (sealing plate) 36 of the door 3, and the adjustment wall 42 is formed by bending the end portion of the front plate 36. Yes. The rear wall 43 is formed so as to make metal contact with the shoulder wall surface 4a when the door 3 is closed. By making metal contact in this way, radio waves leaking from the heating chamber 1 through the periphery of the door 3 can be confined in the heating chamber.

Further, an outer side wall 45 is formed from the front end of the opening 41 so as to face the wall surface (depth direction wall surface) 4b of the heating chamber 1 with a gap 44 of a predetermined interval. An opening 41 is formed by the front end portion of the adjustment wall 42 and the outer side wall 45, and the equivalent capacity C of the choke chamber 40 can be adjusted by adjusting the dimension D of the adjustment wall 42.
A plate-like dielectric 46 is bonded to a portion corresponding to the gap 14. The dielectric 46 prevents radio waves from accumulating in the choke chamber 40 while allowing radio waves to pass through the opening 41 of the choke chamber 40, and obstructs the opening 41 of the choke chamber 40 when the door 3 is opened. Thus, the appearance can be prevented.

  Further, the choke chamber 40 includes a bottom wall 47 that forms the front surface of the choke chamber 40 in a direction perpendicular to the outer side wall 45. The bottom wall 47 forms a short circuit surface of the choke chamber 40.

  Further, the choke chamber 40 includes an inner side wall 48 formed to face the outer side wall 45 and the adjustment wall 42 so as to connect the bottom wall 47 and the rear wall 43. Further, the choke chamber 40 is provided with an overhanging wall 49 extending from the rear end of the opening 41 into the choke chamber 40, that is, from the outer side wall 45 toward the inner side wall 48 in a right angle direction. The overhanging wall 49 divides the chalk chamber 40 into a first groove 50 on the opening 41 side and a second groove 51 on the bottom wall 47 side. A communication port 52 having a predetermined size for communicating the first groove 50 and the second groove 51 is formed between the tip of the overhang wall 49 and the inner side wall 48. The width A of the first groove 50 is smaller than the width B of the second groove 51 (A <B).

  In the microwave oven according to the third embodiment, assuming that the cross-sectional view of FIG. 9 is an xy plane, the choke chamber 40 prevents propagation of radio waves in the x and y directions (see FIG. 4 of the first embodiment). Further, in order to prevent the propagation of radio waves in the z direction (see FIG. 4 of the first embodiment), the choke chamber 40 has a periodic structure in which slits 53 extending from the outer side wall 45 to the overhanging wall 49 are provided at predetermined intervals. Is formed.

  In the microwave oven of the present embodiment configured as described above, the rear wall 43 and the shoulder wall surface 4a of the stepped portion 4 are both formed in parallel with the opening surface of the opening portion 2, and therefore the door 3 is closed. Sometimes it is easy to make both in metal contact. For this reason, radio waves leaking from the heating chamber 1 through the peripheral portion of the door 3 are first enclosed in the heating chamber 1 by metal contact between the rear wall 43 and the stepped portion 4, and the leaked radio waves are greatly reduced. can do.

  Of the radio waves that have passed through the metal contact portion between the rear wall 43 and the stepped portion 4, radio waves in the z direction are leaked by a periodic structure in which slits 53 extending from the outer side wall 45 to the overhanging wall 49 are provided at predetermined intervals. Is prevented. In addition, radio waves in the x and y directions enter the choke chamber 40 through the opening 41, and radio wave leakage is prevented in the choke chamber 40.

Further, the equivalent capacity C of the choke chamber 40 according to this embodiment can be easily adjusted by changing the length D of the adjusting wall 42. In addition, the equivalent capacity C of the choke chamber 10 can be easily adjusted by changing the dimension of the communication port 52 between the first groove 50 and the second groove 51. Furthermore, the equivalent inductance L can be easily adjusted by changing the dimension of the first groove 50.
Therefore, the choke chamber 40 according to the present embodiment can be designed to be a small choke chamber that is optimal for 2450 MHz, which is the fundamental wave of a microwave oven, by changing these dimensions. Can be reduced.

  Further, in the microwave oven according to the present embodiment, the width dimension A of the first groove 50 is smaller than the width dimension B of the second groove 51, so that the characteristic impedance of the second groove 51 is greater than that of the first groove 50. The choke chamber 40 can be easily reduced in size.

  Next, Example 4 will be described with reference to FIGS. 11 and 12. FIG. 11 is a schematic cross-sectional view of the microwave oven according to the fourth embodiment, and FIG. 12 is an enlarged cross-sectional view of the vicinity of the choke chamber of the door in the microwave oven. In addition, the same code | symbol is attached | subjected to the same location as Example 3, and the description is abbreviate | omitted.

The fourth embodiment is obtained by changing the shape of the opening 2 of the heating chamber 1 in the third embodiment.
That is, in Example 4, as shown in FIGS. 11 and 12, the opening 2 on the front surface of the heating chamber 1 is a tapered portion 55 that expands forward. Further, the choke chamber 40 similar to that of the first embodiment is obliquely attached so that the adjusting wall 42 and the outer side wall 45 are along the tapered portion 55 in accordance with the shape of the tapered portion 55 of the opening 2.
In the choke chamber 40 in the fourth embodiment, the rear wall 43 is not in metal contact with the wall surface of the heating chamber 1 because the heating chamber 1 has no stepped portion, but the adjustment wall 42 is the heating chamber as in the first embodiment. It is attached so as to be in contact with or close to the wall surface of 1, specifically, the wall surface of the tapered portion 55.
Although the shape of the dielectric 46 is wedge-like unlike the first embodiment, it may be a flat plate like the first embodiment.

  Since the fourth embodiment is configured as described above, out of the radio waves leaking from the heating chamber 1 through the peripheral portion of the door 3, assuming that the cross-sectional view of FIG. The radio wave (see FIG. 4 according to the first embodiment) is prevented from leaking in the choke chamber 40. Further, leakage of radio waves in the Z direction is prevented by a periodic structure in which slits 53 extending from the outer side wall 45 to the overhanging wall 49 are provided at predetermined intervals. Further, radio waves leaking from the heating chamber 1 through the peripheral portion of the door 3 are contained by the proximity or contact between the adjustment wall 42 and the wall portion of the tapered portion 55.

  In addition, since the opening 2 of the heating chamber 1 is formed in a tapered shape, when the door 3 starts to open, a gap between the adjustment wall 42 and the wall of the tapered portion 55 increases, so that the door is closed. Thus, the adjustment wall 42 and the wall portion of the tapered portion 55 can be made closer to each other, and radio waves leaking from the heating chamber 1 to the outside can be further reduced.

1 is a schematic cross-sectional view of a microwave oven according to Embodiment 1. FIG. It is an expanded sectional view near the chalk chamber of the door in the same microwave oven. It is a perspective view from the front side in the state where the door of the microwave oven was closed. It is a perspective view from the front side in the state which opened the door of the microwave oven, Comprising: It shows in the state which removed the dielectric material. It is a perspective view from the front side of the door in the microwave oven, Comprising: It shows in the state which removed the dielectric material. 6 is a schematic cross-sectional view of a microwave oven according to Embodiment 2. FIG. It is an expanded sectional view near the chalk chamber of the door in the same microwave oven. 6 is a schematic cross-sectional view of a microwave oven according to Embodiment 3. FIG. It is an expanded sectional view near the chalk chamber of the door in the same microwave oven. It is a perspective view from the front side of the door in the microwave oven, Comprising: It shows in the state which removed the dielectric material. 6 is a schematic cross-sectional view of a microwave oven according to Embodiment 4. FIG. It is an expanded sectional view near the chalk chamber of the door in the same microwave oven. It is a schematic sectional drawing of the microwave oven which concerns on a prior art example. It is an expanded sectional view near the chalk chamber of the door in the same microwave oven.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating chamber 2 Opening part 3 Door 4 Step part 4b Depth direction wall surface 4a Shoulder wall surface 5 Flange part 10 Choke chamber 11 Opening 12 Adjustment wall 13 Front wall 14 Crevice 15 Outer side wall 16 Dielectric 17 Bottom wall 18 Inner side wall 19 Overhang Wall 20 First groove 21 Second groove 22 Communication port 23 Slit 25 Tapered portion 40 Choke chamber 41 Opening 42 Adjusting wall 43 Rear wall 44 Clearance 45 Outer side wall 46 Dielectric 47 Bottom wall 48 Inner side wall 49 Overhang wall 50 First groove 51 Second Groove 52 Communication Port 53 Slit 55 Tapered Part A First Groove Width B Second Groove Width

Claims (8)

A heating chamber in which radio waves are supplied to the inside, and a door for opening and closing the opening of the heating chamber,
The door has a choke chamber formed to enter the heating chamber when closed,
The choke chamber has an opening formed so as to face the wall surface of the heating chamber, an adjustment wall that extends forward from the front end of the opening in proximity to or in contact with the wall surface of the heating chamber, and a heating chamber from the rear end of the opening. An outer side wall that faces the wall surface at a predetermined interval, a bottom wall formed on the rear surface orthogonal to the outer side wall, a front wall formed on the front surface orthogonal to the adjustment wall, and a front wall and a bottom wall An inner wall formed opposite to the adjustment wall and the outer side wall so as to connect, a projecting wall extending into the choke chamber from the rear end of the opening toward the inner side wall, and formed on the opening side of the projecting wall The first groove, the second groove formed on the bottom wall side of the overhanging wall, and the communication port formed between the distal end of the overhanging wall and the inner side wall and communicating the first groove and the second groove The microwave oven characterized by having. A heating chamber in which radio waves are supplied to the inside, and a door for opening and closing the opening of the heating chamber,
The door has a choke chamber formed to enter the heating chamber when closed,
The choke chamber has an opening formed so as to face the wall surface of the heating chamber, an adjustment wall extending from the rear end of the opening in the vicinity of or in contact with the wall surface of the heating chamber, and heating from the front end of the opening. An outer side wall facing the wall surface of the chamber at a predetermined interval, a bottom wall of the choke chamber formed on the front surface orthogonal to the outer side wall, a rear wall formed on the rear surface orthogonal to the adjustment wall, and a bottom wall An inner side wall formed to face the outer side wall and the adjustment wall so as to connect the outer wall and the rear wall, a projecting wall extending from the front end of the opening toward the inner side wall into the choke chamber, and an opening side of the projecting wall The first groove formed, the second groove formed on the bottom wall side of the overhanging wall, and the first groove and the second groove formed between the tip of the overhanging wall and the inner side wall communicate with each other. A microwave oven characterized by having a communication port.   2. The microwave oven according to claim 1, wherein the wall surface of the heating chamber has a stepped portion that allows the bottom wall of the choke chamber to abut from the front in the vicinity of the opening of the heating chamber.   The microwave oven according to claim 2, wherein the wall surface of the heating chamber has a stepped portion that allows the rear wall of the choke chamber to come into contact with the front surface in the vicinity of the opening of the heating chamber.   3. The microwave oven according to claim 1, wherein the wall surface of the heating chamber is formed in a tapered shape that spreads forward in the vicinity of the opening. 4.   The microwave oven according to any one of claims 1 to 5, wherein the choke chamber is formed such that a width dimension of the first groove is smaller than a width dimension of the second groove.   The microwave oven according to claim 1, wherein the opening of the choke chamber is formed so as to be covered with a dielectric.   The microwave oven according to any one of claims 1 to 7, wherein the choke chamber has a periodic structure in which slits straddling the outer side wall and the overhanging wall of the choke chamber are provided at predetermined intervals.

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